I do have some questions which is related to adding beneficial bacteria. In the pond, do you require changing water also? like 20% and after wanter change you will have to add again the beneficial bacteria. The same applies to the aquarium especialy if the aquarium is over stocked.. Is this right? Coz I have over stocked my 20 gal tank with 2 pleco & 6
Goldfish. The Local pet shop actually recommend to put beneficial bacteria everyday but i read on label once a week every time I change water

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Can i have your opinion on beneficial bacteria as necessary especially for overstocked tank. I think my tank already cycled.
